Question 2
A box contains 6 blue marbles and some red, purple and yellow marbles. It is known that:
(a) $\frac45$ of the marbles are not purple;
(b) The red and yellow marbles together form $\frac7{10}$ of all the marbles;
(c) The number of blue marbles plus twice the number of red marbles equals $\frac13$ of the total.
How many yellow marbles are in the box?
(a) $\frac45$ of the marbles are not purple;
(b) The red and yellow marbles together form $\frac7{10}$ of all the marbles;
(c) The number of blue marbles plus twice the number of red marbles equals $\frac13$ of the total.
How many yellow marbles are in the box?